88. Metamaterial Magic: Demystifying the Science of Cloaking with Dr. Andrea Alù

[Editor’s Note: As we reported earlier this month, “The Operational Environment is increasingly lethal with the ubiquity of sensors and proliferation of battlefield automation facilitating effective precision and massed strike capabilities. Forces that can be sensed are targeted, and if targeted, are destroyed or rendered inoperable. ” This increasingly transparent battlespace has been wrought by the democratization and convergence of commercial satellite imagery, inexpensive Unmanned Aerial System (UAS)-borne sensing platforms, and the Internet of Everything and Everyone. The resulting web of networked sensors could usher in the end of covert movement for combat units and their associated command and control and logistical support nodes, and with that spell the demise of strategic and operational deception and surprise.

This battlespace transparency is driving a renewed quest for concealment. In today’s episode of The Convergence podcast, we sit down with Dr. Andrea Alù to discuss the reality of invisibility, the science behind metamaterials, and the associated possibilities for the U.S. Army.

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Andrea Alù is a Distinguished Professor, founding director of the Photonics Initiative at the CUNY Advanced Science Research Center, Einstein Professor of Physics at the CUNY Graduate Center, and Professor of Electrical Engineering at The City College of New York. He is affiliated with the Wireless Networking and Communications Group and the Applied Research Laboratories, both based at the University of Texas at Austin, where he is a Senior Research Scientist and Adjunct Professor. His research interests span a broad range of technical areas, including applied electromagnetics, nano-optics and nanophotonics, microwave, THz, infrared, optical and acoustic metamaterials and metasurfaces, plasmonics, nonlinearities and nonreciprocity, cloaking and scattering, acoustics, optical nanocircuits and nanoantennas.

Army Mad Scientist sat down with Dr. Alù to discuss the reality of invisibility, the science behind metamaterials, and the associated possibilities for the U.S. Army. The following bullet points highlight key insights from our conversation:

• Alù’s work focuses on wave physics, specifically looking at how to structure materials at the nanoscale to change their interactions with waves – light, sound, and radio – and demonstrate phenomena that would not be possible otherwise, for example invisibility.These new structured materials are called metamaterials because their properties go beyond those of natural materials.

• By structuring materials in specific ways, a “cloak” can be created and, when wrapped around an object, can suppress the scattering of light or waves which is what allows the object to be visible. This process causes a transparency effect on the object, effectively causing it to disappear.

• There is a limit, however, to making an object fully transparentwhen using passive materials which require no energy. There is a tradeoff between the size of the object and the amount of suppression of scattering waves from the object –- the larger the object, the harder it is to achieve full suppression of the scattering waves.